Comparison of Optical Coherence Angiography Measurements in Patients with Neovascular and Non-Neovascular Age-Related Macular Degeneration

Objectives: The purpose of the study was to determine the differences of optical coherence tomography angiography (OCTA) measurements between the patients with neovascular age-related macular degeneration (AMD) and non-neovascular early AMD. Methods: This retrospectively designed study included patients with neovascular AMD (N-AMD group) and non-neovascular early AMD (NN-AMD group). The patients had a completed ocular examination including best-corrected visual acuity (BCVA, in decimal), intraocular pressure (IOP, mmHg), and OCTA measurements such as choroidal blood flow (au) and retinal vessel density (VD, %). Results: The N-AMD group (1.46 +/- 0.28 au) showed a lower mean choroidal flow measurement than the NN-AMD group (1.73 +/- 0.32 au), (p<0.001). The patients in the N-AMD group had reduced VD measurements in all superficial and deep retinal layers compared with the NN-AMD group. However, significant differences in VD measurements were observed only in total superficial parafovea and in the superior and inferior quadrants of superficial parafovea while comparing the N-AMD and NN-AMD groups (p<0.05 for all). Almost all deep retinal VD measurements (p<0.05 for them) were significantly different in the N-AMD group except the overall and foveal zones (p=0.144 and p=0.433, respectively). Conclusion: Retinal VD is reduced in patients with N-AMD when compared to NN-AMD. This outcome offered a retinal vessel contribution to AMD pathogenesis.